Hi All - I have a 2001 C200 Kompressor Elegance Auto (approx 250,000km's) that last weekend started blowing clouds of smoke when I accelerate (no noticeable change in performance) first thought was to pension the old girl off to the wreckers. Next day jumped into it and noticed 'no smoke' for about the first 10km at which time (warmed up) I noted that when accelerating there was a rattling sound which if I had to guess seemed to be coming from under the car rather than the engine bay. The smoking returned with the start of the rattling and have noticed the 2 definitely go together - hear the rattle/see the smoke. Any clues anyone? If it's a matter of replacing 1 thing the old girl might be worth saving.

What colour smoke? if it is whiteish it could be trans fluid. I don't know your model but some have a vacuum modulator on the trans and if the diaphragm goes in it the vacuum sucks the fluid up into the engine and burns it off. Might fit with low trans fluid and the rattle? Also if lots of smoke, check all the fluids and might hint as to what it is burning.

CraigB wrote:What colour smoke? if it is whiteish it could be trans fluid. I don't know your model but some have a vacuum modulator on the trans and if the diaphragm goes in it the vacuum sucks the fluid up into the engine and burns it off. Might fit with low trans fluid and the rattle? Also if lots of smoke, check all the fluids and might hint as to what it is burning.

Thanks CraigB - it's black/blue smoke and in fact the end of the weekend trip came up with a 'low coolant' malfunction message & I thought 'ahh head gasket' but coolant wasn't down very much at all, no sign of oil in the coolant and as I said previously no discernible loss of performance. So I thought low coolant message might be just a coincidence. I will check the transmission fluid though - thanks for the tip!